Clinical and Radiographic Survival Rates of the Arthrex Univers VaultLock Uncemented Central-Peg All-Polyethylene Glenoid Component in Anatomic Total Shoulder Arthroplasty at 2- and 5-Years Postoperatively.

BACKGROUND: To evaluate radiographic and functional outcomes at 2 and 5 years postoperatively for anatomic total shoulder arthroplasty (aTSA) performed with an uncemented central-peg all-polyethylene glenoid (Univers VaultLock; Arthrex, Inc., Naples, FL) designed for an uncemented central-peg fixation with peripheral cement and central osseous interdigitation.

METHODS: This was a multi-center retrospective case series of aTSAs identified from a prospectively maintained registry. All primary aTSAs with an intact rotator cuff using a VaultLock glenoid (uncemented central-peg all-polyethylene design) and available radiographic data were included for analysis at 2- and 5-years postoperatively. Primary outcomes included radiographic glenoid loosening (via Lazarus classification) and revision rates for glenoid loosening. Relevant changes in lucency were defined as change in Lazarus score ≥ 2 and an "at-risk" component for loosening was defined as Lazarus score ≥ 3. Secondary outcomes included range of motion, as well as patient-reported outcomes.

RESULTS: A total of 133 patients were included in the overall cohort, of whom 119 met criteria for analysis of radiographic and patient-reported outcomes at 5 years. The mean age was 63.9 ± 7.8 years, with an average body mass index (BMI) of 30.2 ± 4.9 kg/m2 and mean follow-up of 5.0 ± 0.4 years. All outcome measures significantly improved at 2- and 5-years compared to baseline. At 2 years, 111 patients (93.3%) demonstrated a grade 0-1 Lazarus score, while 8 patients (6.7%) had a grade 2 Lazarus score. No glenoids at 2 years were observed to have grade 3 changes consistent with being "at-risk" for radiographic loosening. At 5 years, 100 patients (84.0%) had a grade 0-1 Lazarus score, 13 patients (11.0%) had a grade 2 Lazarus score, and 6 patients (5.0%) had a grade 3 or greater Lazarus scores. 40 (33.6%) patients had an increase in Lazarus score from 2 to 5 years with mean increase of 1.2 (SD 0.42, Range: 1-2). At 5 years, central peg humeral head bone grafting was associated with lower rates of Lazarus score ≥2 versus no grafting (9.5% vs 23.2%, p = 0.042). Clinical survival rate was 99.2% (132/133) at 5-years postoperatively, with radiographic survival of 95.0% (113/119) at 5-years postoperatively.

CONCLUSIONS: The VaultLock glenoid has a 5-year clinical and radiographic glenoid survival rate of 99.2% and 95.0%, respectively. These findings are consistent with or superior to prior published reports of all-polyethylene glenoids and supports the use of a uncemented central-peg all-polyethylene component in primary TSA.

LEVEL OF EVIDENCE: Level IV, Case Series, Treatment Study.